Which of the following is true about time fences in a master production schedule system?

In a master production schedule (MPS) system, time fences are critical because they delineate different time periods within which changes to the production schedule can vary in their cost and feasibility. The correct answer highlights that changes made far out in the planning horizon can generally be accomplished with minimal disruption to the production process. This is largely due to the fact that there is more lead time to accommodate revisions, allowing for adjustments in resource allocation, inventory levels, and production strategy without significant detriment to operations.

The rationale behind this is rooted in the flexibility associated with longer-term planning. As the production date approaches, constraints on capacity and materials become more pronounced, and the potential for conflicts with existing commitments, such as staffing levels, supplier agreements, and customer orders, increases. Thus, planning further in advance affords manufacturers more options to optimize resources and mitigate costs.

The other options reflect misunderstandings of the operational dynamics at play within specified time fences. The frozen zone is characterized by a high degree of commitment to existing orders, making it costly and challenging to incorporate new changes. Similarly, changes that occur closer to the present date are typically more impactful on production schedules and therefore generally carry higher costs. Additionally, allowing the master planner authority over the frozen zone could disrupt established commitments